Mamr writer with low resistance mamr stack

ABSTRACT

The present disclosure generally relates to a magnetic media drive employing a magnetic recording head. The head includes a main pole at a media facing surface (MFS), a trailing shield at the MFS, and a MAMR stack disposed between the main pole and the trailing shield at the MFS. The MAMR stack includes a seed layer and at least one magnetic layer. The seed layer is fabricated from a thermally conductive material having electrical resistivity lower than that of the main pole. The seed layer has a stripe height greater than a stripe height of the at least one magnetic layer. With the extended seed layer, the bias current from the trailing shield to the main pole spreads further away from the MFS along the extended seed layer before flowing into the main pole, reducing temperature rise at or near the MAMR stack, leading to improved write head reliability.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of co-pending U.S. patent applicationSer. No. 16/017,909, filed Jun. 25, 2018, which claims benefit of U.S.Provisional Application Ser. No. 62/606,142, filed on Oct. 5, 2017. Eachof the aforementioned related patent applications is herein incorporatedby reference.

BACKGROUND Field of the Disclosure

Embodiments of the present disclosure generally relate to data storagedevices, and more specifically, to a magnetic media drive employing amagnetic recording head.

Description of the Related Art

Over the past few years, microwave assisted magnetic recording (MAMR)has been studied as a recording method to improve the areal density of amagnetic read/write device, such as a hard disk drive (HDD). MAMRenabled magnetic recording heads utilize a MAMR stack disposed betweenthe trailing shield and the main pole to improve write field and/orfield gradient, leading to better areal density capability (ADC). TheMAMR stack may include a seed layer and at least one magnetic layer,such as a spin torque layer (STL) that is magnetized by a bias currentduring operation. Alternatively, the MAMR stack may include spin torqueoscillator (STO) for generating a microwave (high frequency AC magneticfield). When a bias current is conducted to the STO from the main pole,the STO oscillates and provides an AC magnetic field to the recordingmedium. The AC magnetic field may reduce the coercive force of therecording medium, thus high quality recording by MAMR may be achieved.Typically the STO includes a seed layer, a spin polarization layer(SPL), a field generation layer (FGL) and an interlayer disposed betweenthe SPL and the FGL.

However, Joule heating induced by the bias current can cause asignificant temperature rise at and near the MAMR stack, causingdegradation of the MAMR stack and/or the main pole and the trailingshield in the vicinity of the MAMR stack. Therefore, there is a need inthe art for an improved data storage device.

SUMMARY OF THE DISCLOSURE

The present disclosure generally relates to a magnetic media driveemploying a magnetic recording head. The head includes a main pole at amedia facing surface (MFS), a trailing shield at the MFS, and a MAMRstack disposed between the main pole and the trailing shield at the MFS.The MAMR stack includes a seed layer and at least one magnetic layer.The seed layer is fabricated from a thermally conductive material havingelectrical resistivity lower than that of the main pole. The seed layerhas a stripe height greater than a stripe height of the at least onemagnetic layer. With the extended seed layer, the bias current from thetrailing shield to the main pole spreads further away from the MFS alongthe extended seed layer before flowing into the main pole, reducingtemperature rise at or near the MAMR stack, leading to improved writehead reliability.

In one embodiment, a magnetic recording head includes a main pole, atrailing shield, and a stack disposed between the main pole and thetrailing shield, wherein the stack includes a seed layer having a firststripe height and at least one magnetic layer having a second stripeheight, and wherein the first stripe height is greater than the secondstripe height.

In another embodiment, a magnetic recording head includes a main pole, atrailing shield, a stack disposed between the main pole and the trailingshield, wherein the stack includes a seed layer having a first portionand a second portion, and at least one magnetic layer disposed on thefirst portion. The magnetic recording head further includes a dielectricmaterial disposed on the second portion of the seed layer.

In another embodiment, a data storage device includes a magnetic writehead having a trailing shield, a main pole, a stack disposed between themain pole and the trailing shield, wherein the stack includes a magneticlayer having a first stripe height, and a current blocking layerdisposed between the stack and the main pole at a media facing surface,wherein the current blocking layer has a second stripe height less thanthe first stripe height.

In another embodiment, a magnetic recording head includes a main pole, astack coupled to the main pole, and means for directing a bias currentaway from the main pole at a media facing surface.

In another embodiment, a magnetic recording head is disclosed comprisinga main pole, a trailing shield and a stack disposed between the mainpole and the trailing shield, wherein the stack includes a seed layerhaving a first stripe height and at least one magnetic layer having asecond stripe height, and wherein the first stripe height is equal tothe second stripe height.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentdisclosure can be understood in detail, a more particular description ofthe disclosure, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this disclosure and are therefore not to beconsidered limiting of its scope, for the disclosure may admit to otherequally effective embodiments.

FIG. 1 is a schematic illustration of a magnetic media device accordingto one embodiment disclosed herein.

FIG. 2 is a fragmented, cross sectional side view of a read/write headfacing a magnetic disk according to one embodiment disclosed herein.

FIG. 3 is a cross sectional side view of the portion of the write headof FIG. 2 according to one embodiment disclosed herein.

FIGS. 4A-4C are MFS views of the portion of the write head of FIG. 2according to embodiments disclosed herein.

FIG. 5A is a cross sectional side view of the portion of the write headaccording to another embodiment disclosed herein.

FIG. 5B is a MFS view of the portion of the write head according toanother embodiment disclosed herein.

FIG. 6 is a cross sectional view of a seed layer stack according to oneembodiment disclosed herein.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements disclosed in oneembodiment may be beneficially utilized on other embodiments withoutspecific recitation.

DETAILED DESCRIPTION

The present disclosure generally relates to a magnetic media driveemploying a magnetic recording head. The head includes a main pole at amedia facing surface (MFS), a trailing shield at the MFS, and a MAMRstack disposed between the main pole and the trailing shield at the MFS.The MAMR stack includes a seed layer and at least one magnetic layer.The seed layer is fabricated from a thermally conductive material havingelectrical resistivity lower than that of the main pole. The seed layerhas a stripe height greater than a stripe height of the at least onemagnetic layer. With the extended seed layer, the bias current from thetrailing shield to the main pole spreads further away from the MFS alongthe extended seed layer before flowing into the main pole, reducingtemperature rise at or near the MAMR stack, leading to improved writehead reliability.

The terms “over,” “under,” “between,” and “on” as used herein refer to arelative position of one layer with respect to other layers. As such,for example, one layer disposed over or under another layer may bedirectly in contact with the other layer or may have one or moreintervening layers. Moreover, one layer disposed between layers may bedirectly in contact with the two layers or may have one or moreintervening layers. In contrast, a first layer “on” a second layer is incontact with the second layer. Additionally, the relative position ofone layer with respect to other layers is provided assuming operationsare performed relative to a substrate without consideration of theabsolute orientation of the substrate.

FIG. 1 is a schematic illustration of a data storage device such as amagnetic media device. Such a data storage device may be a singledrive/device or comprise multiple drives/devices. For the sake ofillustration, a single disk drive 100 is shown according to oneembodiment. As shown, at least one rotatable magnetic disk 112 issupported on a spindle 114 and rotated by a drive motor 118. Themagnetic recording on each magnetic disk 112 is in the form of anysuitable patterns of data tracks, such as annular patterns of concentricdata tracks (not shown) on the magnetic disk 112.

At least one slider 113 is positioned near the magnetic disk 112, eachslider 113 supporting one or more magnetic head assemblies 121 that mayinclude a MAMR stack disposed between a trailing shield and a main pole.As the magnetic disk 112 rotates, the slider 113 moves radially in andout over the disk surface 122 so that the magnetic head assembly 121 mayaccess different tracks of the magnetic disk 112 where desired data arewritten. Each slider 113 is attached to an actuator arm 119 by way of asuspension 115. The suspension 115 provides a slight spring force whichbiases the slider 113 toward the disk surface 122. Each actuator arm 119is attached to an actuator means 127. The actuator means 127 as shown inFIG. 1 may be a voice coil motor (VCM). The VCM includes a coil movablewithin a fixed magnetic field, the direction and speed of the coilmovements being controlled by the motor current signals supplied bycontrol unit 129.

During operation of the disk drive 100, the rotation of the magneticdisk 112 generates an air bearing between the slider 113 and the disksurface 122 which exerts an upward force or lift on the slider 113. Theair bearing thus counter-balances the slight spring force of suspension115 and supports slider 113 off and slightly above the disk surface 122by a small, substantially constant spacing during normal operation.

The various components of the disk drive 100 are controlled in operationby control signals generated by control unit 129, such as access controlsignals and internal clock signals. Typically, the control unit 129comprises logic control circuits, storage means and a microprocessor.The control unit 129 generates control signals to control various systemoperations such as drive motor control signals on line 123 and headposition and seek control signals on line 128. The control signals online 128 provide the desired current profiles to optimally move andposition slider 113 to the desired data track on disk 112. Write andread signals are communicated to and from write and read heads on theassembly 121 by way of recording channel 125.

The above description of a typical magnetic media device and theaccompanying illustration of FIG. 1 are for representation purposesonly. It should be apparent that magnetic media devices may contain alarge number of media, or disks, and actuators, and each actuator maysupport a number of sliders.

FIG. 2 is a fragmented, cross sectional side view of a read/write head200 facing the magnetic disk 112 according to one embodiment. Theread/write head 200 may correspond to the magnetic head assembly 121described in FIG. 1. The read/write head 200 includes a MFS 212, such asan air bearing surface (ABS), facing the disk 112, a magnetic write head210, and a magnetic read head 211. As shown in FIG. 2, the magnetic disk112 moves past the write head 210 in the direction indicated by thearrow 232 and the read/write head 200 moves in the direction indicatedby the arrow 233.

In some embodiments, the magnetic read head 211 is a magnetoresistive(MR) read head that includes an MR sensing element 204 disposed betweenMR shields S1 and S2. In other embodiments, the magnetic read head 211is a magnetic tunnel junction (MTJ) read head that includes a MTJsensing device 204 disposed between MR shields S1 and S2. The magneticfields of the adjacent magnetized regions in the magnetic disk 112 aredetectable by the MR (or MTJ) sensing element 204 as the recorded bits.

The write head 210 includes a main pole 220, a leading shield 206, atrailing shield 240, a MAMR stack 230 disposed between the main pole 220and the trailing shield 240, and a coil 218 that excites the main pole220. The coil 218 may have a “pancake” structure which winds around aback-contact between the main pole 220 and the trailing shield 240,instead of a “helical” structure shown in FIG. 2. The MAMR stack 230 maybe in contact with the main pole 220 and the trailing shield 240. In oneembodiment, a trailing shield hot seed layer 241 is coupled to thetrailing shield 240, and MAMR stack 230 is in contact with the main pole220 and the trailing shield hot seed layer 241. A dielectric material254 is disposed between the leading shield 206 and the main pole 220.The main pole 220 includes a trailing taper 242 and a leading taper 244.The trailing taper 242 extends from a location recessed from the MFS 212to the MFS 212. The leading taper 244 extends from a location recessedfrom the MFS 212 to the MFS 212. The trailing taper 242 and the leadingtaper 244 may have the same degree of taper, and the degree of taper ismeasured with respect to a longitudinal axis 260 of the main pole 220.In some embodiments, the main pole 220 does not include the trailingtaper 242 and the leading taper 244. Instead, the main pole 220 includesa trailing side (not shown) and a leading side (not shown), and thetrailing side and the leading side are substantially parallel. The mainpole 220 may be a magnetic material such as a FeCo alloy. The leadingshield 206 and the trailing shield 240 may be a magnetic material, suchas NiFe alloy. The trailing shield hot seed layer 241 may include a highmoment sputter material, such as FeCo, CoFeN or FeXN, where X includesat least one of Rh, Al, Ta, Zr, and Ti.

The MAMR stack 230 includes a seed layer 234 and one or more layers 236.The seed layer 234 may be a single layer or a layer stack including morethan one layer. The seed layer 234 is fabricated from a thermallyconductive material having electrical resistivity lower than that of themain pole 220. The seed layer 234 may be fabricated from a non-magneticmetal or alloys, such as copper (Cu), chromium (Cr), ruthenium (Ru),tungsten (W), gold (Au), silver (Ag), tin (Sn), molybdenum (Mo), iridium(Ir), platinum (Pt), or rhodium (Rh). In one embodiment, the seed layer234 has a lower electrical resistivity than that of tantalum. In oneembodiment, the one or more layers 236 include a magnetic layer, such asa STL, and a spacer layer. In one embodiment, the magnetic layer isNiFe, CoMnGe, or CoFe. The spacer layer is fabricated from a materialsuch as Cu or AgSn. In another embodiment, the one or more layers 236includes a first magnetic layer, such as a SPL, a second magnetic layer,such as an FGL, and an interlayer disposed between the SPL and the FGL.As shown in FIG. 2, the seed layer 234 extends further away from the MFS212 than the one or more layers 236. The MAMR stack 230 is described indetail below.

FIG. 3 is a cross sectional side view of a portion of a write head 210according to one embodiment. As shown in FIG. 3, the write head 210includes the trailing shield 240, the MAMR stack 230, the dielectricmaterial 254, and the main pole 220. In some embodiments, the trailingshield hot seed layer 241 (not shown) may be coupled to the trailingshield 240 (FIG. 2). The main pole 220 and the trailing shield 240 aredisposed at the MFS 212. The MAMR stack 230 is disposed between the mainpole 220 and the trailing shield 240 at the MFS 212. The dielectricmaterial 254 is disposed between the main pole 220 and the trailingshield 240 at a location recessed from the MFS 212. The main pole 220includes the trailing taper 242 in contact with the MAMR stack 230. Inone embodiment, as shown in FIG. 3, the MAMR stack 230 includes the seedlayer 234, a magnetic layer 302, and a spacer layer 304. The magneticlayer 302 may be a STL and may be NiFe, CoMnGe, or CoFe. The spacerlayer 304 may be fabricated from a material such as Cu or AgSn.

The seed layer 234 includes a first portion 306 and a second portion308. The first portion 306 has a stripe height SH₁, the second portion308 has a stripe height SH₂, and the seed layer 234 has a stripe heightSH₃. The stripe height SH₃ equals the stripe height SH₁ plus the stripeheight SH₂. The magnetic layer 302 or the spacer layer 304 has the samestripe height SH₁. Thus, the stripe height SH₃ of the seed layer 234 isgreater than the stripe height SH₁ of the magnetic layer 302 or thespacer layer 304. The stripe heights SH₁, SH₂ and SH₃ are measured byperpendicular distances between ends of the layer or portion of thelayer. In one embodiment, the stripe height SH₁ ranges from about 40 nmto about 100 nm, the stripe height SH₂ ranges from about 5 nm to aboutone or more microns. Because the second portion 308 of the seed layer234 has electrical resistivity lower than that of the main pole 220, thebias current from the trailing shield flows through the second portion308 of the seed layer 234 before flowing into the main pole 220,effectively reducing the current crowding at the MAMR stack 230 and thetotal device resistance. In addition, temperature rise at or near theMAMR stack 230 is reduced, leading to improved head reliability andlifetime. In some embodiments, the second portion 308 is fabricated froma material different than the material of the first portion 306 of theseed layer 234.

The first portion 306 of the seed layer 234 is disposed between the mainpole 220 at the MFS 212 and the magnetic layer 302. The second portion308 of the seed layer 234 is disposed between the main pole 220 at alocation recessed from the MFS 212 and the dielectric material 254. Inone embodiment, the first portion 306 and the second portion of the seedlayer 234 are disposed on the main pole 220, the magnetic layer 302 isdisposed on the first portion 306 of the seed layer 234, and thedielectric material 254 is disposed on the second portion 308. Thedielectric material 254 is adjacent the magnetic layer 302 and thespacer layer 304. The dielectric material 254 is in contact with thetrailing shield 240.

The first portion 306 of the seed layer 234 has a thickness T₁, and thesecond portion 308 of the seed layer 234 has a thickness T₂. In oneembodiment, the thickness T₁ is the same as the thickness T₂. In anotherembodiment, the thickness T₁ is greater than the thickness T₂ due toover-etching of the material disposed on the second portion 308 of theseed layer 234.

FIGS. 4A-4C are MFS views of the portion of the write head 210 of FIG. 2according to embodiments disclosed herein. As shown in FIG. 4A, thewrite head 210 includes the trailing shield 240, the main pole 220, theMAMR stack 230 disposed between the trailing shield 240 and the mainpole 220, and side shields 402, 404. The main pole 220 is disposedbetween the side shields 402, 404 in the cross track direction. Thedielectric material 254 is disposed between the trailing shield 240 andthe side shields 402, 404 and between the main pole 220 and the sideshields 402, 404. The MAMR stack 230 includes the seed layer 234, themagnetic layer 302, and the spacer layer 304. As shown in FIG. 4A, theMAMR stack 230 has a uniform width W₁ in the cross track direction. Inother words, the seed layer 234, the magnetic layer 302, and the spacerlayer 304 all have the width W₁. The seed layer 234 includes the firstportion 306 at the MFS 212 and the second portion 308 (FIG. 3) recessedfrom the MFS 212.

As shown in FIG. 4B, the write head 210 includes the trailing shield240, the main pole 220, the MAMR stack 230 disposed between the trailingshield 240 and the main pole 220, and the side shields 402, 404. TheMAMR stack 230 includes the seed layer 234, the magnetic layer 302, andthe spacer layer 304. As shown in FIG. 4B, the magnetic layer 302 andthe spacer layer 304 each have the width W₁ in the cross trackdirection, and the seed layer 234 has a width W₂ in the cross trackdirection. In one embodiment, the width W₂ is greater than the width W₁,and the seed layer 234 laterally extends beyond the width W₁ of themagnetic layer 302. The laterally extended seed layer 234 can alsoeffectively reduce the current crowding at the MAMR stack 230 and thetotal device resistance. With the laterally extended seed layer 234, thesecond portion 308 (FIG. 3) recessed from the MFS 212 may or may not bepresent.

As shown in FIG. 4C, the write head 210 includes the trailing shield240, the main pole 220, the MAMR stack 230 disposed between the trailingshield 240 and the main pole 220, and the side shields 402, 404. TheMAMR stack 230 includes the seed layer 234, the magnetic layer 302, andthe spacer layer 304. As shown in FIG. 4C, the magnetic layer 302 andthe spacer layer 304 each have a width W₁ in the cross track direction,and the seed layer 234 has a width W₂ in the cross track direction. Inone embodiment, the width W₂ is greater than the width W₁, and the seedlayer 234 laterally extends beyond the width W₁ of the magnetic layer302. A metal side gap 405 surrounds the main pole 220 at the MFS 212.The metal side gap 405 includes a first portion 406, a second portion408, and a third portion 410. The main pole 220 includes a first surface412 disposed at the MFS 212, a second surface 414 connected to the firstsurface 412, a third surface 416 opposite the second surface 414, afourth surface 418 connecting the second surface 414 and the thirdsurface 416, and a fifth surface 420 opposite the fourth surface 418.The seed layer 234 is disposed on the second surface 414 of the mainpole 220. The first portion 406 of the metal side gap 405 is disposedbetween the fourth surface 418 of the main pole 220 and the side shield402, the second portion 408 of the metal side gap 405 is disposedbetween the third surface 416 of the main pole 220 and the leadingshield 206 (FIG. 2), and the third portion 410 of the metal side gap 405is disposed between the fifth surface 420 of the main pole 220 and theside shield 404. The first portion 406 of the metal side gap 405 and thethird portion 410 of the metal side gap 405 are in contact with the seedlayer 234. Because the metal side gap 405 are fabricated from a metal,which is thermally conductive, dissipating of heat generated at or nearthe MAMR stack 230 is increased. With the laterally extended seed layer234, the second portion 308 (FIG. 3) recessed from the MFS 212 may ormay not be present.

In some embodiments, the temperature of the main pole 220 at the MFS 212is reduced by placing a current blocking layer between a portion of theMAMR stack 230 and the main pole 220 at the MFS 212. FIG. 5A is a crosssectional side view of the portion of the write head 210 according toanother embodiment disclosed herein. As shown in FIG. 5A, the write head210 includes the trailing shield 240, the MAMR stack 230, the main pole220, and current blocking layer 502 disposed between the MAMR stack 230and the main pole 220. In some embodiments, the trailing shield hot seedlayer 241 (not shown) may be coupled to the trailing shield 240 (FIG.2). The main pole 220 and the current blocking layer 502 are disposed atthe MFS 212. The main pole 220 includes the trailing taper 242 incontact with the current blocking layer 502 at the MFS 212 and the MAMRstack 230 at a location recessed from the MFS 212. The current blockinglayer 502 is fabricated from a material having substantially higherelectrical resistivity than that of the main pole 220. The currentblocking layer 502 may be fabricated from MgO, AlO_(x), TaO_(x), or SiN.The thickness T₃ of the current blocking layer 502 is no greater than 3nm. The current blocking layer 502 may block or minimize the biascurrent flowing to the main pole 220 at the MFS 212, which in turnlowers the temperature of the main pole 220 at the MFS 212, leading toimproved write head reliability and lifetime.

In one embodiment, as shown in FIG. 5A, the MAMR stack 230 includes theseed layer 234, the magnetic layer 302, and the spacer layer 304. Theseed layer 234 includes the first portion 306. The current blockinglayer 502 is in contact with a portion of the first portion 306 of theseed layer 234. In one embodiment, the seed layer 234 includes thesecond portion 308, as shown in FIG. 5A to further direct the flow ofthe bias current away from the MFS 212. The thickness T₂ of the secondportion 308 of the seed layer 234 may be equal to or greater than thethickness T₁ of the first portion 306 of the seed layer 234. In anotherembodiment, the seed layer 234 does not include the second portion 308,and the MAMR stack 230 has a uniform stripe height SH₁. In oneembodiment, the first portion 306 of the seed layer 234, the magneticlayer 302, and the spacer layer 304 all have the stripe height SH₁. Thecurrent blocking layer 502 has a stripe height SH₄. The stripe heightSH₄ is about 15 percent to about 85 percent of the stripe height SH₁. Inone embodiment, the stripe height SH₁ ranges from about 40 nm to about100 nm, and the stripe height SH₄ ranges from about 20 nm to about 80nm.

FIG. 5B is a MFS view of the portion of the write head 210 according toanother embodiment disclosed herein. As shown in FIG. 5B, the write head210 includes the trailing shield 240, the main pole 220, the MAMR stack230 disposed between the trailing shield 240 and the main pole 220, thecurrent blocking layer 502 disposed between the MAMR stack 230 and themain pole 220, and the side shields 402, 404. The metal side gap 405surrounds the main pole 220 at the MFS 212. The MAMR stack 230 includesthe seed layer 234, the magnetic layer 302, and the spacer layer 304.The current blocking layer 502 is disposed at the MFS 212 between theseed layer 234 of the MAMR stack 230 and the second surface 414 of themain pole 220. In one embodiment, as shown in FIG. 5B, the magneticlayer 302 and the spacer layer 304 each have the width W₁ in the crosstrack direction, the seed layer 234 has the width W₂ in the cross trackdirection, and the current blocking layer 502 has a width W₂ in thecross track direction. In one embodiment, the width W₂ is greater thanthe width W₁, the width W₁ is greater than the width W₃. With thecombination of the current blocking layer 502, the laterally extendedseed layer 234, and the metal side gap 405, the bias current flows intothe metal side gap 405 instead of into the main pole 220. In anotherembodiment, the width W₂ is the same as the width W₁, and the width W₃is smaller than widths W₁, W₂. With the laterally extended seed layer234, the second portion 308 (FIG. 3) recessed from the MFS 212 may ormay not be present.

FIG. 6 is a cross sectional view of a seed layer stack 600 according toone embodiment disclosed herein. The seed layer stack 600 may replacethe seed layer 234 shown in FIGS. 2, 3, 4A-4C, 5A and 5B. The seed layerstack 600 includes more than one layer, such as two, three or morelayers. As shown in FIG. 6, the seed layer stack 600 includes a firstlayer 602, a second layer 604, and a third layer 606. Each of the firstlayer 602, second layer 604, and third layer 606 is fabricated from Cu,Pt, Au, Ag, Sn, Ru, Cr, W, Mo, Ir, or Rh, which has lower electricalresistivity than that of Ta. In one embodiment, the first layer 602 isfabricated from Cu, the second layer 604 comprises W or Cr, and thethird layer 606 comprises Ru.

The benefits of having a MAMR stack including an extended seed layerhaving greater stripe height and/or greater width than the rest of thelayers of the MAMR stack include reducing temperature rise at or nearthe MAMR stack since the bias current is directed away from the MFS. Thetemperature of the main pole can be further reduced by including acurrent blocking layer between the main pole and the MAMR stack, whichfurther blocks the bias current from flowing into the main pole at theMFS. With less or no current flowing to the main pole at the MFS, thetemperature of the main pole is reduced, leading to improved write headreliability and lifetime.

In one example embodiment, a magnetic recording head, comprising a mainpole, a trailing shield; and a stack disposed between the main pole andthe trailing shield, wherein the stack includes a seed layer having afirst stripe height and at least one magnetic layer having a secondstripe height, and wherein the first stripe height is greater than thesecond stripe height.

In one example embodiment, the magnetic recording head may be providedwherein the first stripe height is at least 5 nm greater than the secondstripe height.

In another non-limiting embodiment, the magnetic recording head may beprovided wherein the seed layer has a lower electrical resistivity thanthat of the main pole.

In another non-limiting embodiment, the magnetic recording head may beprovided wherein the seed layer comprises non-magnetic metal.

In another non-limiting embodiment, the magnetic recording head may beprovided wherein the seed layer comprises copper (Cu), chromium (Cr),ruthenium (Ru), tungsten (W), gold (Au), silver (Ag), tin (Sn),molybdenum (Mo), iridium (Ir), platinum (Pt), or rhodium (Rh).

In another non-limiting embodiment, a magnetic recording head isdisclosed comprising a main pole, a trailing shield, a stack disposedbetween the main pole and the trailing shield, wherein the stackcomprises: a seed layer having a first portion and a second portion, andat least one magnetic layer disposed on the first portion; and adielectric material disposed on the second portion of the seed layer.

In another non-limiting embodiment, the magnetic recording head may beprovided wherein the first portion of the seed layer and the secondportion of the seed layer comprise a same material.

In another non-limiting embodiment, the magnetic recording head may beprovided wherein the first portion of the seed layer and the secondportion of the seed layer comprise different materials.

In a still further non-limiting embodiment, the magnetic recording headmay be provided wherein the at least one magnetic layer has a firststripe height, the first portion of the seed layer has a second stripeheight, the second portion of the seed layer has a third stripe height,and the seed layer has a fourth stripe height.

In another non-limiting embodiment, the magnetic recording head may beprovided wherein the first stripe height is the same as the secondstripe height.

In another non-limiting embodiment, the magnetic recording head may beconfigured wherein the fourth stripe height equals a sum of the secondstripe height and the third stripe height.

In a still further non-limiting embodiment, the magnetic recording headmay be configured wherein the third stripe height is 5 nm or greater.

In another non-limiting embodiment, the magnetic recording head may beconfigured wherein the dielectric material is in contact with the atleast one magnetic layer.

In another non-limiting embodiment, a data storage device is disclosedcomprising a magnetic write head, comprising a trailing shield, a mainpole, a stack disposed between the main pole and the trailing shield,wherein the stack includes a magnetic layer having a first stripe heightand a current blocking layer disposed between the stack and the mainpole at a media facing surface, wherein the current blocking layer has asecond stripe height less than the first stripe height.

In another non-limiting embodiment, the data storage device may beconfigured wherein the second stripe height is about 15 percent to about85 percent of the first stripe height.

In another non-limiting embodiment, the data storage device may beconfigured wherein the current blocking layer has a thickness of 3 nm orless.

In another non-limiting embodiment, the data storage device may beconfigured wherein the current blocking layer comprises MgO, AlO_(x),TaO_(x), or SiN.

In another example embodiment, the data storage device may furthercomprise a seed layer having a third stripe height, wherein the thirdstripe height is greater than first stripe height.

In one example embodiment, a magnetic recording head is disclosedcomprising a main pole, a stack coupled to the main pole and means fordirecting a bias current away from the main pole at a media facingsurface.

In another non-limiting embodiment, the magnetic recording head may beconfigured wherein the means for directing the bias current away fromthe main pole at the media facing surface is located between the mainpole and the stack.

In another non-limiting embodiment, a magnetic recording head isdisclosed comprising a main pole, a trailing shield; and a stackdisposed between the main pole and the trailing shield, wherein thestack includes a seed layer having a first stripe height and at leastone magnetic layer having a second stripe height, and wherein the firststripe height is equal to the second stripe height.

In another non-limiting embodiment, the magnetic recording head may beconfigured wherein the seed layer has a lower electrical resistivitythan that of the main pole.

In another non-limiting embodiment, the magnetic recording head may beconfigured wherein the seed layer comprises non-magnetic metal.

In another non-limiting embodiment, the magnetic recording head may beconfigured wherein the seed layer comprises at least one of copper,chromium, gold, silver and platinum.

In another non-limiting embodiment, the magnetic recording head may beconfigured wherein the seed layer comprises at least one of chromium,ruthenium, tungsten, tin, molybdenum, iridium and rhodium.

While the foregoing is directed to embodiments of the presentdisclosure, other and further embodiments of the disclosure may bedevised without departing from the basic scope thereof, and the scopethereof is determined by the claims that follow.

1. A magnetic recording head, comprising: a main pole; a trailingshield; and a stack disposed between the main pole and the trailingshield, wherein the stack includes a seed layer having a first stripeheight and at least one magnetic layer having a second stripe height,and wherein the first stripe height is greater than the second stripeheight.
 2. The magnetic recording head of claim 1, wherein the firststripe height is at least 5 nm greater than the second stripe height. 3.The magnetic recording head of claim 1, wherein the seed layer has alower electrical resistivity than that of the main pole.
 4. The magneticrecording head of claim 1, wherein the seed layer comprises non-magneticmetal.
 5. The magnetic recording head of claim 4, wherein the seed layercomprises copper (Cu), chromium (Cr), ruthenium (Ru), tungsten (W), gold(Au), silver (Ag), tin (Sn), molybdenum (Mo), iridium (Ir), platinum(Pt), or rhodium (Rh).
 6. A magnetic recording head, comprising: a mainpole; a trailing shield; a stack disposed between the main pole and thetrailing shield, wherein the stack comprises: a seed layer having afirst portion and a second portion; and at least one magnetic layerdisposed on the first portion; and a dielectric material disposed on thesecond portion of the seed layer.
 7. The magnetic recording head ofclaim 6, wherein the first portion of the seed layer and the secondportion of the seed layer comprise a same material.
 8. The magneticrecording head of claim 6, wherein the first portion of the seed layerand the second portion of the seed layer comprise different materials.9. The magnetic recording head of claim 6, wherein the at least onemagnetic layer has a first stripe height, the first portion of the seedlayer has a second stripe height, the second portion of the seed layerhas a third stripe height, and the seed layer has a fourth stripeheight.
 10. The magnetic recording head of claim 9, wherein the firststripe height is the same as the second stripe height.
 11. The magneticrecording head of claim 10, wherein the fourth stripe height equals asum of the second stripe height and the third stripe height.
 12. Themagnetic recording head of claim 11, wherein the third stripe height is5 nm or greater.
 13. The magnetic recording head of claim 6, wherein thedielectric material is in contact with the at least one magnetic layer.14. A data storage device, comprising: a magnetic write head,comprising: a trailing shield; a main pole; a stack disposed between themain pole and the trailing shield, wherein the stack includes a magneticlayer having a first stripe height; and a current blocking layerdisposed between the stack and the main pole at a media facing surface,wherein the current blocking layer has a second stripe height less thanthe first stripe height.
 15. The data storage device of claim 14,wherein the second stripe height is about 15 percent to about 85 percentof the first stripe height.
 16. The data storage device of claim 14,wherein the current blocking layer has a thickness of 3 nm or less. 17.The data storage device of claim 14, wherein the current blocking layercomprises MgO, AlO_(x), TaO_(x), or SiN.
 18. The data storage device ofclaim 14, wherein the stack further comprises seed layer having a thirdstripe height, wherein the third stripe height is greater than firststripe height.
 19. A magnetic recording head, comprising: a main pole; astack coupled to the main pole; and means for directing a bias currentaway from the main pole at a media facing surface.
 20. The magneticrecording head of claim 19, wherein the means for directing the biascurrent away from the main pole at the media facing surface is locatedbetween the main pole and the stack.
 21. A magnetic recording head,comprising: a main pole; a trailing shield; and a stack disposed betweenthe main pole and the trailing shield, wherein the stack includes a seedlayer having a first stripe height and at least one magnetic layerhaving a second stripe height, and wherein the first stripe height isequal to the second stripe height.
 22. The magnetic recording head ofclaim 21, wherein the seed layer has a lower electrical resistivity thanthat of the main pole.
 23. The magnetic recording head of claim 21,wherein the seed layer comprises non-magnetic metal.
 24. The magneticrecording head of claim 21, wherein the seed layer comprises at leastone of copper, chromium, gold, silver and platinum.
 25. The magneticrecording head of claim 21, wherein the seed layer comprises at leastone of chromium, ruthenium, tungsten, tin, molybdenum, iridium andrhodium.